WASHINGTON, D.C.--A small Pentagon mission to fire probes into several near-Earth asteroids has been shot down itself. President Bill Clinton last week vetoed the Clementine 2 program, part of the 1998 Defense Department budget that Congress recently sent the president. Clinton used his new line-item veto authority to cut defense spending by nearly $150 million, most of which was to be spent on military research programs not requested by the Administration but added by lawmakers.

Clementine 2 was an ambitious follow-on to a 1994 mission to the moon and an asteroid sponsored by the Strategic Defense Initiative Organization. While the spacecraft failed before reaching its asteroid target, it did gather data on possible signs of water ice in a crater near the moon's south pole. A second mission was planned for launch in 1998, but the $125 million program has been delayed by a bitter fight between the Administration and Congress.

Some Pentagon and White House officials argued that the Clementine 2 mission went too far afield from national security, while some Republicans in Congress backed it as a high-tech attempt to learn more about intercepting objects in space while gathering useful scientific data. The Defense Department didn't even request funding for the program in 1998, but Congress gave it a $30 million increase. Clinton now has the ability to veto individual parts of bills, and he wielded his pen against Clementine 2. But program supporters are not giving up. They hope to salvage at least part of the mission so that it could at least rendezvous with an Earth-orbiting satellite.

In the defense bill, Clinton also cut $4 million set aside for Army research into a proton beam machine that could be used against cancer, $10 million for Navy research into hypersonic technology that could lead to an advanced space plane, and $2 million for toxic-waste cleanup research.